Body Control Systems

U0019-CAN B BUS

U0019 - Can B Bus:

WHEN MONITORED
Continuously

SET CONDITION
Whenever the CAN B Bus (+) or CAN B Bus (-) circuit is open, shorted to voltage or shorted to ground.

POSSIBLE CAUSES
- CAN B BUS DTC's in the totally integrated power module
- (D55) CAN B BUS (+) circuit open
- (D54) CAN B BUS (-) circuit open
- Hands free module

Diagnostic Test

1. CHECK FOR ACTIVE DTCS

With the scan tool, read the active DTC's.
Cycle the ignition switch from off to on at least 5 times, leaving the ignition on for a minimum of 90 seconds per cycle.
With the scan tool, read the active DTC's.

Q: Does the scan tool display this DTC as active?

YES: Go To 2
NO: If the DTC is stored, check for an intermittent condition. Visually inspect the related wiring harness connectors. Look for broken, bent, pushed out, or corroded terminals.

2. CHECK THE TOTALLY INTEGRATED POWER MODULE DTC's

With the scan tool, read the Totally Integrated Power Module active DTC's.

Q: Does the scan tool display any CAN B BUS DTC's - ACTIVE?

YES: Refer to Manufacturer Code Charts / Communication.
NO: Go To 3




3. (D55) CAN B BUS (+) CIRCUIT OPEN

Turn the ignition off.
Disconnect the negative battery cable.
Disconnect the Hands Free Module harness connector.
Disconnect the Totally Integrated Power Module harness connector. Measure the resistance of the (D55) CAN B Bus (+) circuit between the Totally Integrated Power Module connector and the Hands Free Module connector.

Q: Is the resistance below 2.0 ohms?

YES: Go To 4
NO: Repair the (D55) CAN B Bus (+) circuit for an open. Perform the BODY VERIFICATION TEST - VER 1. Body Verification Test




4. (D54) CAN B BUS (-) CIRCUIT OPEN

Measure the resistance of the (D54) CAN B Bus (-) circuit between the Totally Integrated Power Module connector and the Hands Free Module connector.

Q: Is the resistance below 2.0 ohms?

YES: Replace the Hands Free Module. Perform the BODY VERIFICATION TEST - VER 1. Body Verification Test
NO: Repair the (D54) CAN B Bus (-) circuit for an open. Perform the BODY VERIFICATION TEST - VER 1. Body Verification Test